e-conservation the online Magazine 16, oct 2010.pdf

IDENTIFICATION OF IVORY BOOK COVERS
is present, and any other colour or no colour change
indicates cellulose nitrate is not present [6]. This
test would have been successful in determining
that the brown book was in fact cellulose nitrate,
but not aid in identifying the other books.
Scientific Analysis
Finally, a conclusive test was administered. Scott
Williams, Senior Conservation Scientist at the Canadian
Conservation Institute (CCI), performed
Fourier Transform Near Infrared Reflectance Spectroscopy
testing on the four books as well as an
elephant ivory sample [7] (Figure 4). A LabSpec
Pro NIR spectrometer (Analytical Spectral Devices)
with a bifurcated fibre optic reflection probe was
used to gather spectra from each material [7]. The
characterization of the material is determined by
its molecular interaction with the infrared radiation
which originates a characteristic spectrum
[8].The spectra were then arranged on graphs in
comparison with the spectra of reference materials
of known compositions [7].
From the gathered spectra, it is evident that Book
1, Book 2 and Book 3 are each pure elephant ivory
(Figure 5). Every spectrum of each book (except
Book 4) is very closely related to the sample spectra
of a known elephant tusk. However, Book 4 did
not closely compare to the elephant tusk sample
at all. However, it did relate closely to sample spectra
from cellulose nitrate (Figure 6) Therefore, it
was concluded with certainty that Book 1, Book 2,
and Book 3 are made of true elephant ivory, and
Book 4 is made of cellulose nitrate.
History of Ivory Use
Early man utilized as much of mammoths as possible,
beginning the tradition of ivory use in both
utilitarian and decorative objects [3]. Early uses
included weaponry, musical instruments, religious
pieces, personal artifacts, decorative items, artistic
pieces, and parts for games [3]. Ivory became associated
with gold and silver as a luxurious commodity,
used especially for decorating objects of
value [1].
Figure 5. Spectra of Book 1, Book 2, and Book 3 compared to sample ivory (red) (Graph: Scott Williams).
Covers and embellishments for all books
have spectra similar to elephant ivory
(red trace).
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